Playdek today announced its new expansion pack, Nightfall: Martial Law, will be available as an in-app purchase in mid-August. To celebrate the arrival of the Nightfall: Martial Law, Alderac Entertainment Group (AEG) and Playdek will offer the original Nightfall at $.99 for a limited time, starting July 13th. Here is more info on the upcoming pack:

Nightfall: Martial Law introduces many new characters and actions, as well as new color combinations for creating chains and achieving kickers. Martial Law will also introduce the new "Feed" mechanic which will allow players to get even more uses out of their orders. The game also brings to the table a new "Wound" effect that is sure to surprise opponents.

More about Nightfall game:

Nightfall brings AEG's modern horror deck-building game to iOS. As a Universal iOS game application, Nightfall provides a fantastic world and unique game mechanics to everyone with an iPhone 3Gs, iPhone 4 or iPhone 4s, iPad, iPad 2 or iPad HD, iPod Touch 2, iPod Touch 3 or iPod Touch 4.The sun has retreated from the earth. A week ago the sun shone its last and chaos began. People fear for their existence, while scientists struggle to explain the phenomenon. Until they came. The creatures of nightmare -- vampires, werewolves, and ghouls -- have begun to appear throughout the world, and they show no sign of hesitation in claiming the dark world as their own! Nightfall puts players in control of minions of the night, fighting one another for control of an Earth shrouded in eternal night. Werewolves, vampires, ghouls, and those who fight them see no need to hide from the public, waging their war in the streets.

Supports 1-5 players (human and/or AI)Multiplayer online gamesPlay against multiple A.I. opponents using varied strategiesPlay against others with "pass and play" multiplayerIntroductory tutorial to teach you how to playEnhanced visual optimization for iPhone 4 using high resolution graphics designed for the retina displayMaintain and save multiple games